12.(b5) What new feature 'Pages -> Copy Page's should do? After copying couple of pages just site-map is updating, but nothing more

That's pretty alpha here.

You can select a page to copy on the left and a parent page on the right.
If you have widgets in the souce page they will be copied to the new page.
If it's a P2Html widget its content will also be duplicated and linked with the new cell and page.

11.(b5) It's FireFox(all things here is tested on FireFox (I'll notice if problem occurs in other browsers after fixing FF))

We've just generated a lot of bugs/solves/pending solves here, but I have to mention one important P2 weakness here:

Models/Cruds - they are weak in P2 when evaluating with what Yii has now(automatic search, editing buttons, etc.)

In my honourable opinion P2 should use what is already created + that easy CMS system you've just created and still creating eagerly!

9.(b5) After "model client" and "crud client" it does everything seemingly fine but I neither can update nor create any records in the table Client (Is this because ID(auto incremented) is added in the crud's view files)?

Yes, I also thought about it and configured htaccess to have PHP5, of course I checked through phpinfo() link but I still have this problem :/ and my hosting provider is OVH.com it may something to help